Modern motor vehicles sometimes have protective systems which, in the event of a collision, are intended to protect the collision object, when a person is involved, from serious injuries. Such a protection system is the so-called “pedestrian protection”. This protective system has the effect that a front gate, i.e. the engine hood, which is arranged pivotably on the body via two hinge joints, can be raised, i.e. lifted, with the gate end adjacent to the windscreen in opposition to the normal opening swing direction. This raising of the front gate, which is raised by only a few centimeters, creates more clearance and thus space to components located below the front gate, in particular the engine, so that the risk of injury to the person can be reduced in the event of a collision.
DE 10 2005 022 924 A1 discloses a motor vehicle with a front gate, which is arranged pivotably on a body via two hinge joints. Such a hinge has a first hinge limb with a first fastening portion for fastening to the front gate and a second hinge limb with a second fastening portion for fastening to the body, with the two hinge limbs each having articulated sections which are articulated to one another in such a way that the hinge limbs are swingable from a first angular position of the articulated section commensurate with a closed position into a second angular position commensurate with an opening position of the front gate. The angle between the articulation sections changes hereby steadily in one direction. Furthermore, a lifting device is provided which when actuated in the closed position of the front gate distances the first fastening portion from the second fastening portion such that the front gate is raised. The angle during this lifting operation changes in the same direction.
DE 103 43 882 A1 discloses a front gate arrangement on a motor vehicle, with at least one hinge device in the form of a four-bar joint located at the rear in the direction of travel, and including a long arm and a short arm, with the hinge device enabling the front gate to be pivoted for normal opening and closing, and to be raised at the rear region in the event of a collision of the vehicle. To this end, the hinge devices include an energy accumulator that actuates a displacement device in the event of a collision of the vehicle, which displacement device, in turn, acting directly on the front gate and being detachably connected to the same. The joint of the four-bar joint on the side of the front gate is hereby fixed in an articulated manner to a pivoting lever which is detachably fixed to the front gate with one end in the idle state, and pivotable in relation to the front gate with the other end thereof about a rotary articulation arranged on the front gate in the region of the articulation of the displacement device. In a collision of the vehicle, the displacement device raises the front gate in relation to the idle state in such a way that it is guided by the arms of the four-bar joint and by the pivoting lever detaching itself on one side from the front gate.
DE 10 2004 007 858 A1 describes a front gate arrangement on a vehicle, including at least one hinge device in the form of a four-bar joint, via which the front gate can be pivoted during normal opening and closing and can be raised in the rear region in a collision of the vehicle. Such a hinge device has a spring element which in a collision of the vehicle actuates an adjusting lever which, in turn, acts directly on the front gate and bears against the latter directly or via intermediate elements. The front-gate-side joints of the four-bar joint are articulated to a pivoting lever which, in the idle state, is releasably attached to the front gate with one end and can be pivoted relative to the front gate about a swivel joint, arranged in the region of the attachment of the adjusting lever to the front gate. In the event of a collision, the adjusting lever lifts the front gate, guided by the arms of the four-bar joint and the pivot lever detaching on one side from the front gate, in relation to the idle state.
DE 100 55 828 A1 discloses a hinge device for a motor vehicle for articulating a front hood of a motor vehicle in combination with a safety device for displacing the front hood to a raised position. The hinge device has a multi-joint hinge, by which the front hood can be opened from the front of the vehicle. The safety device has at least one actuator which can be actuated via the signals of a sensor system and by which the front hood can be displaced from its closed initial position to a position in which the front hood is raised at least in the region of the front hood. For the safety-related raising of the front hood, the interaction of the hinge device between the front hood and the body can be deactivated or interrupted.
Finally, DE 101 11 146 A1 discloses a pivotable gate of a motor vehicle, having a lock which has a gate-side first lock member and a body-side second lock member, and a hinge which has a gate-side first hinge member and a body-side second hinge member. After opening the lock, with the two lock member being separated from one another, the gate can be swung open and can be catapulted in a release-controlled manner into a gap clearance position with respect to the body in a closed state, in which the two lock members are bound together. For this purpose, the gate is brought into the gap clearance position by the force of at least one force accumulator liberated during release.